The invention relates to a method for adapting the transmission function of a hearing aid to various types of hearing difficulty, and to hearing aids for the implementation of this method. A device of this general type is known from the German Patent No. 15 12 720.
With conventional hearing aids, there are problems in being able to adapt the characteristic data as well as possible to the individual hearing impairments of a person with difficulty in hearing. The electrical properties of hearing aid amplifiers are determined by the structural elements used in the construction and at most can only be varied to a slight extent by external controls. This means that there must be a plurality of hearing aids which differ from one another for instance only in the frequency response to the amplifier.
Hitherto, therefore, it has not been possible to find a uniform form of construction for hearing aids. At the present time alone there are several hundred models on the hearing aid market which can be sorted into classes only by consideration of individual parameters.
A further series of types must be adapted to the dynamic range of an afflicted hearing, this range being changed, for example restricted, with various types of hearing difficulty. These hearing aid amplifiers have additional control loops in order to be able to adjust the output level of the hearing aid to the limits suitable for the hearing for which provision is to be made.
According to one particular construction, such as is described for example in the German Offenlegungsschrift No. 23 16 939, an adaptation can also be effected by the frequency range transmitted by the hearing aid being split into at least two partial ranges, to each of which there is coordinated a separate level control acting independently of the other frequency ranges, with one or more control loops in each case. This construction also results in an extensive system of structural elements, so that there are difficulties in obtaining the small construction which is both customary and desirable in hearing aids.